Diodes Incorporated DDZ9687Q-7

Overview

DDZ9687Q-7 from Diodes Incorporated is a surface-mount, low-current Zener diode in SOD123 package, rated for 4.3 V nominal zener voltage (±5% tolerance), 500 mW power dissipation at TL = +75°C, and specified at 50 µA test current - optimized for low-bias, battery-powered voltage reference and regulation in portable electronics.

For engineers reviewing the DDZ9687Q-7 datasheet, DDZ9687Q-7 pinout, DDZ9687Q-7 application, or DDZ9687Q-7 equivalent, this device serves as a precision, AEC-Q101 qualified voltage clamp in automotive sensor biasing, microcontroller reset circuits, and low-power analog signal conditioning where stable reverse breakdown and minimal leakage (<4 µA @ 2 V) are critical.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain a stable reference voltage across its cathode–anode terminals. Its 4.3 V nominal zener voltage exhibits a temperature coefficient of approximately +0.04 %/°C (per Fig. 17), indicating positive drift with rising junction temperature - suitable for applications requiring predictable, moderate TC behavior.

The device delivers 500 mW power dissipation on FR-4 PCB with standard pad layout, with thermal resistance junction-to-ambient of 340 °C/W and junction-to-lead of 150 °C/W. It features a cathode band marking, matte tin–annealed terminals, and meets AEC-Q101 for automotive use with PPAP capability and IATF 16949 manufacturing compliance.

Key Specifications

Pinout & Package

SOD123 package: molded plastic case (UL 94V-0), cathode marked by band on top surface; terminals are matte tin–annealed over Alloy 42 leadframe, solderable per MIL-STD-202 Method 208.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener voltage reference applications.

Compared with BZX84-C4V3-7-F and MMSZ4V3T1G, DDZ9687Q-7 offers superior automotive qualification (AEC-Q101 + PPAP), tighter leakage (≤4 µA), and validated 500 mW operation at +75°C - making it the optimal choice for thermally demanding, safety-conscious vehicle subsystems.

Availability

DDZ9687Q-7 is available at Aetrix Electronics and suitable for automotive sensor biasing, microcontroller reset circuits, portable medical monitor references, and IoT node voltage clamping requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for DDZ9687Q-7 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

The DDZ96xxQ series belongs to Diodes' AEC-Q101 qualified Zener diode product line, engineered specifically for automotive voltage reference and protection applications demanding high reliability, low leakage, and robust thermal performance in harsh environments.

FAQ

What is the maximum reverse voltage (V_R) that DDZ9687Q-7 can withstand before breakdown?

DDZ9687Q-7 is designed to operate in controlled reverse breakdown at its nominal zener voltage of 4.3 V. Its absolute maximum reverse voltage is not defined separately - instead, the device is characterized for stable breakdown between 4.09 V and 4.52 V at 50 µA test current. Exceeding 4.52 V significantly increases power dissipation and risks thermal runaway if current is not externally limited.

Is DDZ9687Q-7 suitable for use in a 5 V rail overvoltage protection circuit?

No - DDZ9687Q-7 has a nominal zener voltage of 4.3 V and a maximum breakdown voltage of 4.52 V, making it unsuitable for clamping a 5 V rail. Using it in such a configuration would cause continuous conduction and overheating. For 5 V rail protection, select a Zener with nominal voltage ≥5.1 V (e.g., DDZ9689Q-7) or a dedicated TVS diode rated for 5 V standoff.

Does DDZ9687Q-7 require a series current-limiting resistor in all applications?

Yes - a series current-limiting resistor is mandatory to prevent destructive power dissipation. The resistor value must be chosen so that worst-case current (e.g., at maximum input voltage and minimum load) remains within the 500 mW power limit and does not exceed the device's safe operating area, especially during transient events or elevated ambient temperatures.

How does the temperature coefficient affect voltage stability in automotive applications?

DDZ9687Q-7 exhibits a positive temperature coefficient of ~+0.04 %/°C near 4.3 V (per Fig. 17), meaning its zener voltage increases ~1.7 mV/°C. Over the automotive range (−40°C to +125°C), this results in a total shift of ~2.8 V - but since regulation occurs at fixed current (50 µA), actual circuit-level drift depends on bias network design and thermal coupling. Stable performance requires minimizing self-heating and matching thermal time constants.